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Khalifa MM, Martorelli Di Genova B, McAlpine SG, Gallego-Lopez GM, Stevenson DM, Rozema SD, Monaghan NP, Morris JC, Knoll LJ, Golden JE. Dual-Stage Picolinic Acid-Derived Inhibitors of Toxoplasma gondii. ACS Med Chem Lett 2020; 11:2382-2388. [PMID: 33335660 DOI: 10.1021/acsmedchemlett.0c00267] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 10/07/2020] [Indexed: 12/20/2022] Open
Abstract
Toxoplasma gondii causes a prevalent human infection for which only the acute stage has an FDA-approved therapy. To find inhibitors of both the acute stage parasites and the persistent cyst stage that causes a chronic infection, we repurposed a compound library containing known inhibitors of parasitic hexokinase, the first step in the glycolysis pathway, along with a larger collection of new structural derivatives. The focused screen of 22 compounds showed a 77% hit rate (>50% multistage inhibition) and revealed a series of aminobenzamide-linked picolinic acids with submicromolar potency against both T. gondii parasite forms. Picolinic acid 23, designed from an antiparasitic benzamidobenzoic acid class with challenging ADME properties, showed 60-fold-enhanced solubility, a moderate LogD7.4, and a 30% improvement in microsomal stability. Furthermore, isotopically labeled glucose tracing revealed that picolinic acid 23 does not function by hexokinase inhibition. Thus, we report a new probe scaffold to interrogate dual-stage inhibition of T. gondii.
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Affiliation(s)
- Muhammad M. Khalifa
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53703, United States
| | - Bruno Martorelli Di Genova
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Sarah G. McAlpine
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, 190 Collins Street, Clemson, South Carolina 29634, United States
| | - Gina M. Gallego-Lopez
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States
- Morgridge Institute for Research, Madison, Wisconsin 53715, United States
| | - David M. Stevenson
- Department of Bacteriology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States of America
| | - Soren D. Rozema
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53703, United States
| | - Neil P. Monaghan
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, 190 Collins Street, Clemson, South Carolina 29634, United States
| | - James C. Morris
- Eukaryotic Pathogens Innovation Center, Department of Genetics and Biochemistry, Clemson University, 190 Collins Street, Clemson, South Carolina 29634, United States
| | - Laura J. Knoll
- Department of Medical Microbiology and Immunology, University of Wisconsin-Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Jennifer E. Golden
- Pharmaceutical Sciences Division, School of Pharmacy, University of Wisconsin-Madison, 777 Highland Avenue, Madison, Wisconsin 53703, United States
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Tan S, Tong WH, Vyas A. Urolithin-A attenuates neurotoxoplasmosis and alters innate response towards predator odor. Brain Behav Immun Health 2020; 8:100128. [PMID: 34589880 PMCID: PMC8474456 DOI: 10.1016/j.bbih.2020.100128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/04/2020] [Accepted: 08/07/2020] [Indexed: 12/29/2022] Open
Abstract
Neurotoxoplasmosis, also known as cerebral toxoplasmosis, is an opportunistic chronic infection caused by the persistence of parasite Toxoplasma gondii cysts in the brain. In wild animals, chronic infection is associated with behavioral manipulation evident by an altered risk perception towards predators. In humans, reactivation of cysts and conversion of quiescent parasites into highly invasive tachyzoites is a significant cause of mortality in immunocompromised patients. However, the current standard therapy for toxoplasmosis is not well tolerated and is ineffective against the parasite cysts. In recent years, the concept of dietary supplementation with natural products derived from plants has gained popularity as a natural remedy for brain disorders. Notably, urolithin-A, a metabolite produced in the gut following consumption of ellagitannins-enriched food such as pomegranate, is reported to be blood-brain barrier permeable and exhibits neuroprotective effects in-vivo. In this study, we investigated the potential of pomegranate extract and urolithin-A as anti-neurotoxoplasmosis agents in-vitro and in-vivo. Treatment with pomegranate extract and urolithin-A reduced the parasite tachyzoite load and interfered with cyst development in differentiated human neural culture. Administration of urolithin-A also resulted in the formation of smaller brain cysts in chronically infected mice. Interestingly, this phenomenon was mirrored by an enhanced risk perception of the UA-treated infected mice towards predatory cues. Together, our findings demonstrate the potential of dietary supplementation with urolithin-A-enriched food as a novel natural remedy for the treatment of acute and chronic neurotoxoplasmosis. Pomegranate extract reduces T. gondii tachyzoite load and cyst formation in-vitro. Urolithin-A, in part, underlies the anti-T. gondii effect of pomegranate extract. Urolithin-A perturbs cyst development in the brain of chronically infected mice. The reduction in brain cyst burden associates with enhanced fear of infected mice towards cat odor. Dietary supplementation with urolithin-A is a potential therapy for neurotoxoplasmosis.
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Affiliation(s)
- Sijie Tan
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Wen Han Tong
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
| | - Ajai Vyas
- School of Biological Sciences, Nanyang Technological University, Singapore, 637551, Singapore
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Secrieru A, Costa ICC, O’Neill PM, Cristiano MLS. Antimalarial Agents as Therapeutic Tools Against Toxoplasmosis-A Short Bridge between Two Distant Illnesses. Molecules 2020; 25:E1574. [PMID: 32235463 PMCID: PMC7181032 DOI: 10.3390/molecules25071574] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Revised: 03/26/2020] [Accepted: 03/27/2020] [Indexed: 11/16/2022] Open
Abstract
Toxoplasmosis is an infectious disease with paramount impact worldwide, affecting many vulnerable populations and representing a significant matter of concern. Current therapies used against toxoplasmosis are based essentially on old chemotypes, which fail in providing a definitive cure for the disease, placing the most sensitive populations at risk for irreversible damage in vital organs, culminating in death in the most serious cases. Antimalarial drugs have been shown to possess key features for drug repurposing, finding application in the treatment of other parasite-borne illnesses, including toxoplasmosis. Antimalarials provide the most effective therapeutic solutions against toxoplasmosis and make up for the majority of currently available antitoxoplasmic drugs. Additionally, other antiplasmodial drugs have been scrutinized and many promising candidates have emanated in recent developments. Available data demonstrate that it is worthwhile to explore the activity of classical and most recent antimalarial chemotypes, such as quinolines, endoperoxides, pyrazolo[1,5-a]pyrimidines, and nature-derived peptide-based parasiticidal agents, in the context of toxoplasmosis chemotherapy, in the quest for encountering more effective and safer tools for toxoplasmosis control or eradication.
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Affiliation(s)
- Alina Secrieru
- Center of Marine Sciences, CCMAR, Gambelas Campus, University of Algarve, UAlg, 8005-139 Faro, Portugal; (A.S.); (I.C.C.C.)
- Department of Chemistry and Pharmacy, Faculty of Sciences and Technology, FCT, Gambelas Campus, University of Algarve, UAlg, 8005-139 Faro, Portugal
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK;
| | - Inês C. C. Costa
- Center of Marine Sciences, CCMAR, Gambelas Campus, University of Algarve, UAlg, 8005-139 Faro, Portugal; (A.S.); (I.C.C.C.)
- Department of Chemistry and Pharmacy, Faculty of Sciences and Technology, FCT, Gambelas Campus, University of Algarve, UAlg, 8005-139 Faro, Portugal
| | - Paul M. O’Neill
- Department of Chemistry, University of Liverpool, Liverpool L69 7ZD, UK;
| | - Maria L. S. Cristiano
- Center of Marine Sciences, CCMAR, Gambelas Campus, University of Algarve, UAlg, 8005-139 Faro, Portugal; (A.S.); (I.C.C.C.)
- Department of Chemistry and Pharmacy, Faculty of Sciences and Technology, FCT, Gambelas Campus, University of Algarve, UAlg, 8005-139 Faro, Portugal
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Hydroxylamine and Carboxymethoxylamine Can Inhibit Toxoplasma gondii Growth through an Aspartate Aminotransferase-Independent Pathway. Antimicrob Agents Chemother 2020; 64:AAC.01889-19. [PMID: 31907178 DOI: 10.1128/aac.01889-19] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 12/23/2019] [Indexed: 12/19/2022] Open
Abstract
Toxoplasma gondii is an obligate intracellular protozoan parasite and a successful parasitic pathogen in diverse organisms and host cell types. Hydroxylamine (HYD) and carboxymethoxylamine (CAR) have been reported as inhibitors of aspartate aminotransferases (AATs) and interfere with the proliferation in Plasmodium falciparum Therefore, AATs are suggested as drug targets against Plasmodium The T. gondii genome encodes only one predicted AAT in both T. gondii type I strain RH and type II strain PLK. However, the effects of HYD and CAR, as well as their relationship with AAT, on T. gondii remain unclear. In this study, we found that HYD and CAR impaired the lytic cycle of T. gondii in vitro, including the inhibition of invasion or reinvasion, intracellular replication, and egress. Importantly, HYD and CAR could control acute toxoplasmosis in vivo Further studies showed that HYD and CAR could inhibit the transamination activity of rTgAAT in vitro However, our results confirmed that deficiency of AAT in both RH and PLK did not reduce the virulence in mice, although the growth ability of the parasites was affected in vitro HYD and CAR could still inhibit the growth of AAT-deficient parasites. These findings indicated that HYD and CAR inhibition of T. gondii growth and control of toxoplasmosis can occur in an AAT-independent pathway. Overall, further studies focusing on the elucidation of the mechanism of inhibition are warranted. Our study hints at new substrates of HYD and CAR as potential drug targets to inhibit T. gondii growth.
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